The present invention is directed to creating simulated, photographic-quality prints and substrates suitable for use in creating simulated photographic-quality images or prints using non-photographic imaging such as xerography and/or ink jet printing and/or copying. More specifically, the present invention is directed to creating simulated, photographic-quality prints which exhibit an improved optical density.
In the practice of conventional xerography, it is the general procedure to form electrostatic latent images on a xerographic surface by first uniformly charging a charge retentive surface such as a photoreceptor. The charged area is selectively dissipated in accordance with a pattern of activating radiation corresponding to original images. The selective dissipation of the charge leaves a latent charge pattern on the imaging surface corresponding to the areas not exposed by radiation.
This charge pattern is made visible by developing it with toner by passing the photoreceptor past one or more developer housings. In monochromatic imaging, the toner generally comprises black thermoplastic powder particles which adhere to the charge pattern by electrostatic attraction. The developed image is then fixed to the imaging surface or is transferred to a receiving substrate such as plain paper to which it is fixed by suitable fusing techniques.
Recently, there has been a great deal of effort directed to the development of color copiers/printers which utilize the xerographic and/or ink jet imaging process. Such efforts have resulted in the introduction of the Xerox.TM. 5775.TM. copier/printer, the Xerox 4900.TM. and the Fuji Xerox A-Color 635.TM. machine into the market place.
Notwithstanding all the recent development in the area of color printers and copiers there is room for improvement in the quality of color images on paper and synthetic substrates such as MYLAR and TESLIN. The foregoing is particularly true when trying to create photographic-quality images using non-photographic processes.
Attempts at improving conventionally formed color toner images have led to the lamination of xerographic images on paper using a transparent substrate. This procedure has been only partially successful because the lamination process tends to reduce the density range of the print resulting in a print that has less shadow detail. The lamination process also adds significant weight and thickness to the print.
Additionally, it is believed that the aforementioned lamination process doesn't produce good results because typically the color toner images at the interface between the laminate and the toner do not make suitable optical contact. That is to say, the initially irregular toner image at the interface is still irregular (i.e. contains voids) enough after lamination that light is reflected from at least some of those surfaces and is precluded from passing through the toner. In other words, when there are voids between the transparency and toner image, light gets scattered and reflected back without passing through the colored toner. Loss of image contrast results when any white light is scattered, either from the bottom surface of the transparent substrate or from the irregular toner surfaces and doesn't pass through the toner.
A known method of improving the appearance of color xerographic images on a transparent substrate comprises refusing the color images. Such a process was observed at a NOMDA trade shown in 1985 at a Panasonic exhibit. The process exhibited was carried out using an off-line transparency fuser, available from Panasonic as model FA-F100, in connection with a color xerographic copier which was utilized for creating multi-color toner images on a transparent substrate for the purpose of producing colored slides. Since the finished image from the color copier was not really suitable for projection, it was refused using the aforementioned off-line refuser. To implement the process, the transparency is placed in a holder intermediate which consists of a clear relatively thin sheet of plastic and a more sturdy support. The holder is used for transporting the imaged transparency through the off-line refuser. The thin clear sheet is laid on top of the toner layer on the transparency. After passing out of the refuser, the transparency is removed from the holder. This process resulted in an attractive high gloss image useful in image projectors. The refuser was also used during the exhibit for refusing color images on paper. However, the gloss is image-dependent. Thus, the gloss is high in areas of high toner density because the toner refuses in contact with the clear plastic sheet and becomes very smooth. In areas where there is little or no toner the gloss is only that of the substrate. The refuser was also used during the exhibit for refusing color images on paper.
Following is a discussion of additional prior art which may bear on the patentability of the present invention. In addition to possibly having some relevance to the question of patentability, these references, together with the detailed description to follow, may provide a better understanding and appreciation of the present invention. The prior art discussed herein as well as the prior art cited therein is incorporated herein by reference.
U.S. Pat. Nos. 5,327,201 and 5,337,132 granted to Robert E. Coleman on Jul. 5, 1994 and to Abraham Cherian on Aug. 9, 1994, respectively, disclose the creation of simulated photographic prints using xerography. To this end, reverse reading images are formed on a transparent substrate and a backing sheet is adhered to the transparent substrate.
U.S. Pat. Nos. 4,686,163 and 4,600,669 describe an electrophotographic imaging method that uses an element comprising a photoconductive layer on an electrically conducting substrate capable of transmitting actinic radiation to which the photoconductive layer is responsive, and a dielectric support, releasably adhered to the substrate, comprising the photoconductive layer or an overcoat thereof forming a surface of the element capable of holding an applied electrostatic charge. To use the element, the surface of the dielectric support is charged, and the photoconductive layer is imagewise-exposed to actinic radiation, thereby forming a developable electrostatic image on the dielectric surface. The electrostatic image, in turn, is developed with toner to form a first color image. A composite color image is formed on the element by repeating the sequence one or more times with imagewise exposure of the photoconductive layer to actinic radiation transmitted through the substrate, and developing over each preceding image with a different color toner. The composite tone image is transferred with the dielectric support to a receiving element to form a color copy such as a three-color filter array or a color proof closely simulating the color print expected from a full press run. The dielectric support on the photoconductive layer comprised a transparent blend of (vinylacetate-co-crotonic acid, 95/5 mole ratio) and cellulose acetate butyrate. The resulting multicolor proof presented a multicolor toner image against a white paper background and protected by the overlying dielectric support, thus accurately resembling a multicolor print from a full press run. The receiver element to which the dielectric support and composite toner image are transferred can be any suitable material against or through which the toner image is desired to be viewed. The receiver can be print stock, such as paper, upon which a press run will be conducted. The receiver can also be of transparent material such as a polymeric film. With respect to the latter, the invention also contemplates, as an embodiment, transfer of the composite toner image and dielectric support to image-bearing elements such as microfilm or microfiche so that the composite color image forms information in addition to image information already present on such image-bearing elements. In addition, the invention contemplates the use of transparent glass or non birefringen translucent polymeric materials such as cellulose esters for use as the receiver. Receivers manufactured from such materials are suited for use informing three-color filter arrays by the process described herein involving the formation of filter array matrices of the complementary colorants cyan, magenta and yellow in the respective color toner imaging steps. If desirable, the receiver can also contain a suitable overcoat layer adapted to soften under the influence of pressure and heat during the transfer step. In this manner, the adhesion of the dielectric support and composite toner image to the receiver can be enhanced. The electrophotographic element bearing the multicolor toner image is moved to a separate lamination device comprising heated metal and rubber rolls, together forming a nip. The toner image is passed through the nip with and against a white receiver paper at a roll temperature of 100.degree. C. (212.degree. F.) and a pressure of 225 pounds per square inch to effect transfer of the dielectric support and composite image to the receiver followed by peeling off the rest of the electrophotographic element.
U.S. Pat. No. 4,066,802 granted on Jan. 3, 1978 to Carl F. Clemens discloses a method of decalcomania in which a toner image pattern is formed on a transfer member which has been overcoated with an abhesive material. A polymeric sheet is interposed between the toner image and a cloth or other image receiving medium. The polymeric sheet assists in the permanent adherence of the toner imaging pattern to the cloth material or other medium when the composite is subjected to heat and pressure. The transfer member and method of its use are set forth. Another embodiment discloses the use of a solvent to fix the image to a cloth material.
U.S. Pat. No. 5,065,183 granted on Nov. 12, 1991 to Morofuji et al. discloses a multicolor printing method for printing multicolor picture images upon a material or object to be printed comprises the steps of, in accordance with a first embodiment of the invention, the formation of a multicolor toner image upon a flexible belt by means of electrophotographic printing methods or techniques, and the transfer of such multicolor toner image directly to the material or object to be printed, such as, for example, a container made of, for example, metal, paper, plastic, glass, or the like, by means of a thermo-transferring process. In accordance with a second embodiment of the invention, the multicolor toner image is formed upon a plastic film, which is laminated upon the flexible belt, by means of electrophotographic printing methods or techniques, and the plastic film is then transferred to and fused upon the container. In accordance with a third embodiment of the invention, a photoconductive member is irradiated by means of exposure light upon a rear surface thereof wherein the multicolor picture images are also formed by electrophotographic printing methods or techniques. In this manner, previously formed toner images upon the photoconductive member do not interfere with the image exposure processing.
U.S. Pat. No. 5,126,797 granted on Jun. 30, 1992 to Forest et al. discloses a method and apparatus for laminating toner images wherein a toner image on a receiving sheet is laminated using a transparent laminating sheet fed from the normal copy sheet supply of a copier, printer or the like. The laminating sheet is fed into laminating contact with the toner image after the toner image has been formed on a receiving sheet. The resulting sandwich is fed through the fuser laminating the image between the sheets. The invention is particularly usable in forming color transparencies.
U.S. Pat. No. 5,108,865 granted to Zwaldo et al on Apr. 28, 1992 discloses a method including the steps of: contacting an image (preferably multi-toned image) with a transfer web(intermediate receptor layer) comprising in sequence, a carrier layer, a transferable release layer, and a releasable adhesive layer (releasable from the carrier layer along with the transferable release layer so that both layers transfer at once), said adhesive layer being in contact with said toned image, said contacting being done under sufficient heat and/or pressure to enable said toned image to be adhered to said releasable adhesive layer with greater strength than the adherence of said toned image to said imaging surface of said photoconductive layer; separating the transfer web and said photoconductive layer so that the toned image is removed from said photoconductive layer and remains adhered to the adhesive layer of the transfer web; contacting the surface of the transfer web having both the multi-toned image and adhesive thereon with a permanent receptor removing the carrier layer of the transfer web from the adhesive and the release layer of the transfer web so that an image article is formed of the permanent receptor, multi-toned image, releasable adhesive, and the resultant surface coating of the release layer which is furthest away from the permanent receptor.
U.S. patent application Ser. No. 07/828,821 filed on Jan. 31, 1992 now abandoned discloses a method and apparatus for enhancing color fidelity in a printing process employing an intermediate member wherein a developing unit deposits a colorless and transparent material directly onto an intermediate member before transfer of any color toner images thereto. Alternatively, a developing unit first deposits the colorless and transparent material on a latent image member. The colorless and transparent material is then transferred to the intermediate member before transfer of any color toner images thereto.
U.S. Pat. No. 5,330,823 granted on Jul. 19, 1994 to Shadi L. Malhotra discloses a substantially transparent recording sheet which comprises (a) a substantially transparent substrate; (b) a binder polymer coated on the substrate; and (c) particles of an antistatic component which are present on at least the surface of the binder polymer coating. The ten patents cited in this patent are incorporated herein by reference.
U.S. patent application Ser. No. D/95576 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. The backing sheet is coated with a polymer material having substantially the same index of refraction as the toner materials used for forming the toner images.
U.S. patent application Ser. No. D/95570 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse or wrong reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. The backing sheet is coated with a polymer material which serves as an adhesive and has a glass transition temperature less than 55.degree. C. A second coating on the backing sheet which contacts the aforementioned polymer includes a hydrophilic polymer material having a melting point greater than 50.degree. C. and a luminescent materials.
U.S. patent application Ser. No. D/95579 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse or wrong reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. The backing sheet is coated with a polymer material which serves as an adhesive and has a glass transition temperature less than 55.degree. C. A hydrophilic polymer coating having a melting point greater than 50.degree. C. and a toner plasticizer having a melting point less than 75.degree. C. contacting the adhesive polymer serves as a wetting agent for providing an enhanced optical interface as well as protection for the adhesive polymer which has a lower melting point than the adhesive polymer.
U.S. patent application Ser. No. D/95576Q2 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse or wrong reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. The backing sheet is coated with a polymer material which serves as an adhesive and has a glass transition temperature less than 55.degree. C. A hydrophilic polymer coating having a melting point less 50.degree. C. contacting the adhesive polymer serves as a wetting agent for providing an enhanced optical interface as well as protection for the adhesive polymer which has a lower melting point than the adhesive polymer.
U.S. patent application Ser. No. D/95580 (Attorney's Docket No.) an apparatus and method for creating color images which are coated with a composition including a lightfastness inducing material and a hydrophobic polymeric binder which protects the images from rough handling and degradation from exposure to UV light.
U.S. patent application Ser. No. D/95582 (Attorney's Docket No.) relates to a method and apparatus wherein coated sheets or substrates such as paper, opaque MYLAR, TESLIN or the like are utilized in the creation of simulated, photographic-quality prints formed using non photographic imaging procedures such as xerography and ink jet. A first substrate which is transparent has a reverse reading image formed thereon. Such an image may be formed using conventional color xerography. A second substrate having a right reading image containing different information from the first substrate is adhered to the imaged side of first substrate. The foregoing results in a simulated photographic-quality print which when viewed through the non-imaged side of the transparent substrate contains all right reading information.
U.S. patent application Ser. No. D/95581 (Attorney's Docket No.) relates to coated sheets or substrates such as paper, opaque MYLAR, TESLIN or the like are utilized in the creation of simulated, photographic-quality prints formed using non photographic imaging procedures such as xerography and ink jet. A first substrate which is transparent has a reverse reading black image formed thereon. Such an image may be formed using conventional monochromatic xerography. A second substrate is xerographically imaged for forming a uniform color image layer thereon. The foregoing results in a simulated color photographic-quality print which when viewed through the non-imaged side of the transparent substrate contains all right reading reading images which exhibit color even though they are formed using black toner.
U.S. patent application Ser. No. D/95577 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. One side of the backing sheet is adhered to a transparent substrate containing a reverse reading image. The opposite surface of the backing sheet is coated with a hydrophilic material which enables writing on that surface with pen or pencil and printing thereon using xerography or ink jet.
U.S. patent application Ser. No. D/95576Q1 (Attorney's Docket No.) relates to a method and apparatus W, herein simulated photographic-quality prints are created using non-photographic imaging such as xerography and ink jet. Reverse reading toner images are formed on a transparent substrate which is adhered to a coated backing sheet. The backing sheet is coated with a lightfastness material for minimizing degradation of color images exposed to UV light.
U.S. patent application Ser. No. D/95578 (Attorney's Docket No.) relates to a method and apparatus wherein simulated photographic-quality prints having one surface or side of a backing sheet provided with a coating which is scuff resistant and which is receptive to being written on with pen or pencil as well as being receptive to xerographic imaging.